Dynamic pile-driving shoes

ABSTRACT

An annulus encircles the lower end portion of a pile which is impacted at its upper end. The annulus contains a radially contractable and expansible collar consisting of a plurality of individual segments, and an expansible and contractable hollow ring is interposed between the annulus and the collar. The collar is actuated by hydraulic fluid under pulsating pressure, so that the collar segments impart vibration to the pile while it is being driven into the earth. The hollow ring has at least two segmental sections each spanning only a portion of the total number of collar segments, and the hydraulic fluid supply is controllable by valves so that the ring segments may be actuated in unison or in alternating succession.

United States Patent Olsen et al.

[ Feba 29, 1972 [54] DYNAMIC FILE-DRIVING SHOES [73] Assignee: saidBassett, by said Olsen [22] Filed: July 14, 1970 [21] Appl. No.: 54,774

[52] U.S.Cl ..175/56,61/53.5, 175/19, 175/56, 175/103, 175/171 [51]lnt.Cl ..E21b 1/06 [58] Field oiSeai-ch ..175/1923, 94, 175/92, 171,402, 56,103;61/53.5

[56] References Cited UNITED STATES PATENTS 848,395 3/1907 Raymond..175/21 2,360,803 10/1944 Steuerman ..l75/21X Begemann ..175/19 Harris..6l/53.5

Primary ExaminerMarvin A. Champion Assistant Examiner-Richard E. FavreauAttorney-Jerry B. Cesak [57] ABSTRACT An annulus encircles the lower endportion of a pile which is impacted at its upper end. The annuluscontains a radially contractable and expansible collar consisting of aplurality of individual segments, and an expansible and contractablehollow ring is interposed between the annulus and the collar. The collaris actuated by hydraulic-fluid under pulsating pressure, so that thecollar segments impart vibration to the pile while it is being driveninto the earth. The hollow ring has at least two segmental sections eachspanning only a portion of the total number of collar segments, and thehydraulic fluid supply is controllable by valves so that the ringsegments may be actuated in unison or in alternating succession.

8 Claims, 6 Drawing Figures PAIENTED FEB 29 I972 SHEET 1 OF 2 FIG.2.

PATENTEDFEBZS 1912 3. 645,345

sum 2 or 2 FIG.6.

|NVENTOR$= HORACE W. OLSEN MAX BASSETT DYNAMIC PILE-DRIVING SHOES Thisinvention relates to new and useful improvements in the an of piledriving, and while it is applicable generally to driving of piles intothe earth, it is particularly concerned with pile driving into thebottom of oceans, lakes and other bodies of water, for the purpose ofanchoring offshore oil-drilling equipment, marine platforms, dockfacilities, dam installations, and the like.

The piles commonly used in this environment are openended and theirdriving into the sea bed is resisted by skin friction both outside andinside the pile. As driving continues, at some depth the inside skinfriction or plug resistance increases to a value which exceeds the forcerequired to produce a bearing failure below the pile tip and, as aresult, the pile ceases to core the earth and becomes plugged, thusmaking it difficult, if not impossible, to drive the pile to a greaterdepth.

Some efforts have been made to eliminate this difficulty by placing aso-called shoe on the lower end portion of the pile which is driven intothe earth, such efforts being based on the theory that skin frictionwould be reduced by the increased area of displacement which the shoeaffords. However, such conventional shoes, rigidly secured to the pile,have not been very successful in their intended purpose and, under someconditions of soil have not been successful at all.

It is, therefore, the principal object of the invention to provide animproved pile-driving shoe which, rather than being static or rigidlyfixed to the pile, is of a dynamic nature and capable of impartingvibrations to the lower end portion of the pile so as to substantiallyminimize internal soil resistance and skin friction and therebymaterially facilitate penetration of the pile into the earth.

As such, the dynamic shoe of the invention consists of a pile-encirclingannulus which contains a radially contractable and expansible collarcomposed of a plurality of individual segments. An expansible andcontractable hollow ring is interposed between the annulus and thecollar and is actuated by hydraulic fluid under pulsating pressure sothat the collar segments impart vibrations to the lower end portion ofthe pile on which the shoe is positioned, to substantially minimizeinternal soil resistance and skin friction as the pile is driven intothe earth. The arrangement is such that the collar segments may beactuated either in unison or in alternate succession, as may bedesirable under different soil conditions.

With the foregoing more important object and features in view and suchother objects and features which may become apparent as thisspecification proceeds, the invention will be understood from thefollowing description taken in conjunction with the accompanyingdrawings, in which like characters of reference are used to designatelike parts, and in which:

FIG. 1 is a fragmentary view, partly in elevation and partly in verticalsection, showing the shoe of the invention applied to a pile which isbeing driven into the sea bed to anchor an offshore platform;

FIG. 2 is a diagrammatic view of the hydraulic system used for actuatingthe shoe;

FIG. 3 is an enlarged plan view of the shoe per se;

FIG. 4 is a vertical sectional view of the shoe, taken substantially inthe plane of the line 4-4 in FIG. 3;

FIG. 5 is an enlarged sectional view, taken substantially in the planeof the line 5-5 in FIG. 3 and showing one of the collar segments in itsoutwardly moved or expanded position;

FIG. 6 is a view similar to that in FIG. 5, but showing the collarsegment in its inwardly moved or contracted position.

Referring now to the accompanying drawings in detail, more particularlyto FIG. 1, the same illustrates a portion of an offshore platform 12supported on the sea bed 13 by a plurality of legs, only one of which isshown as consisting of a tubular jacket 14 through which an anchoringpile 15 is driven into the sea bed. The driving of the pile is effectedin the conventional manner by delivering impacts to its upper end, as bya power hammer or pile driver 16 suspended from a crane 17. The dynamicshoe of the invention, designated generally by the reference numeral 18,is applied to the lower end portion of the pile 15, it being understoodthat some clearance usually exists between the outside diameter of thepile and the inside diameter of the jacket 14 so that the pile with theshoe thereon may be passed downwardly through the jacket and driven intothe sea bed, the shoe remaining on the pile when the driving operationhas been completed.

Reference is now drawn to FIGS. 3-6 which show the shoe 18 in detail.The same comprises an annulus 19 which is of sufficient diameter tofreely encircle the pile 15 and is provided on the inside thereof with aradially contractable and expandible collar 20 consisting of a pluralityof individual collar segments 20a. These collar segments, made of metal,are mounted by individual pivot pins 21 in bearing blocks 22 which aresecured at circumferentially spaced points to the inside of the annulus19. The collar is radially contracted when the collar segments 20 areswung radially inwardly about the pins 21 to the position shown in FIG.6. Conversely, the collar is expanded when the segments 20a are swungradially outwardly in the direction of the annulus to the position shownin FIG. 5. An inclined annular shield 23 is secured to the inside of theannulus 19 below the collar 20 and overlaps the bearings 22 and thepivoted lower portions of the collar segments 20a, whereby to preventsoil from gaining access to or plugging up the pivotal mountings of thesegments when the shoe with the pile is being driven into the earth.

An annular member 24 with a downtumed marginal lip 25 is secured to theinside of the annulus 19 above the collar 20, and a bumper ring 27 ofelastic material is positioned below the member 24 at the inside of thelip 25. The collar segments 20a are provided at their upper end withdetents 28 and when the segments are moved radially inwardly to theposition shown in FIG. 6, the detents 28 come into engagement with thebumper ring 27 and thus stop means are provided for limiting the extentof inward movement of the collar segments. As this occurs, the elasticbumper ring 27 is compressed against the lip 25 and when the force whichmoved the collar segments inwardly ceases, expansion of the elastic ring27 biases the collar segments outwardly in the direction of the annulus19.

The contractable and expansible collar 20 is actuated by an expansibleand contractable ring 29 of elastomeric material, which ring isinterposed between the annulus l9 and the collar sections or segments20a, so that when the ring 29 is expanded by hydraulic fluid underpressure, the collar 20 is contracted and, conversely, when the ring 29is contracted, the collar 20 is expanded by movement of the collarsegments 20a outwardly under the bias of the bumper ring 27. In thecontracted position of the collar 20, the segments 20a come intopositive engagement with the pile 15, while in the expanded position ofthe collar the positive engagement of the segments with the pile issubstantially relaxed, if not fully separated. Thus, by alternatelycontracting and expanding the collar 20, a series of vibrations may beimparted to the lateral surface of the pile 15. These vibrations mayhave a fairly high frequency and may be produced by very small pivotalmovement of the collar segments 200, not necessarily as large as mayseem from a comparison of FIGS. 5 and 6 where the extent of movement hasbeen exaggerated for illustrative purposes.

Under some soil conditions it may be desirable to vibrate the pile byalternately contracting and expanding all of the collar segments 20a isunison. Under other soil conditions it may be preferred to actuate thecollar segments sequentially, as for example, by contracting the collarsegments on one side of the pile and expanding those on the oppositeside of the pile. To afford such sequential actuation, the actuatingring 29 is divided into a plurality of segmental sections which areisolated from each other and each of which has a circumferential spanextending over only a portion of the total number of the collar segments20a. Possibly, a separate actuating ring section may be provided foreach collar segment, but satisfactory results can be obtained if theactuating ring is composed of only two substantially semicircularsections, as shown at 290 and 29b in FIG. 3, where each of the ringsections spans onehalf of the total number of collar segments 20a.

Hydraulic fluid under pulsating pressure is delivered to the two ringsections 29a, 29b by separate conduits 31, 32, respectively, whichextend upwardly from the annulus 19, either along the outside or theinside of the pile to a junction block 33 which is provided on theoutside of the pile adjacent its upper end, as will be apparent fromFIG. 1. Inside the annulus 19, the aforementioned annular member 24 maybe interrupted or recessed as shown in FIG. 3 to afford clearance forthe conduits 31, 32.

The junction block 33 near the upper end of the pile 15 consists of twoseparable members 33' and 33", the member 33' being secured to the pileand having the conduits 31, 32 connected thereto. The member 33" isremovable from the member 33' and has connected thereto conduits 34, 35which communicate with the respective conduits 31, 32 when the members33', 33" are coupled together. Suitable sealing means 36 are provided toprevent leakage at the points of connection of the conduits 31, 32 withthe conduits 34, 35. The conduits 34, 35, which for most part mayconsist of flexible hoses, extend from the junction block 33 to ahydraulic system on the platform 12, the details of the hydraulic systembeing hereinafter described. In the meantime it may be noted that whenthe pile is composed of a number of sections which are driven insuccession and are welded in series as the driving continues, each pilesection is provided with the conduits 31, 32 having a junction blockmember 33 at their upper end and a junction block member 33" at theirlower end, so that as each pile section is added, the conduits 31, 32are correspondingly extended by connecting the block member 33" at thelower end of the added pile section to the block member 33' at the upperend of the preceding pile section, while the block member 33' at theupper end of the added section is connected to the member 33" on theconduits 34, 35.

The hydraulic system shown diagrammatically in FIG. 2 includes a fluidreservoir or tank 40 supplying fluid through a line 41 to a motor-drivenpup 42, the pump having a discharge line 43 extending to a pair ofmanually operable shutofl valves 44, 45. A bypass line 46, equipped withan excess pressure relief valve 47, extends from the discharge line 43to a fluid return line 48 for the tank 40.

The valve 44 communicates with one port of a four-way valve 49, anotherport of which communicates with the aforementioned conduit 34 and hencewith the conduit 31 leading to the ring section 29a in the shoe 18. Athird port of the valve 49 communicates with the conduit 35 and hencewith the conduit 32 leading to the ring section 29b. The fourth port ofthe valve 49 is connected as at 50 to the fluid return line 48. Theconduit 34 has a branch 51 provided with a release valve 52 andsimilarly the conduit 35 has a branch 53 provided with a release valve54, both the valves 52 and 54 discharging into the return line 4 8.

The valve 45 communicates by a branched line 55 with a pair of checkvalves 56, 57, the valve 56 being connected to the conduit 34 and thevalve 57 being connected to the conduit 35, as will be readily apparent.

in operation, assuming that the pump 42 is energized, the valve 44 isopen, the valve 45 is closed and the four-way valve 49 is in theposition shown in FIG. 2, fluid flows from the pump through the openvalve 44 and through the valve 49 into the conduits 34, 31 and into thering section 29a, thus expanding the latter and causing the collarsegments a spanned by the ring section 2911 to contract or move inwardlyinto positive engagement with the adjacent side portion of the pile l5.Simultaneously, the valve 49 permits backflow or drainage of fluid fromthe ring section 29b through the conduits 32, 35 and 48 to the tank 40,so that the collar segments 20a which are spanned by the ring section29b are relaxed from their positive engagement with the opposite sideportion of the pile 15.

When fluid pressure in the ring section 29a builds up to a predeterminedvalue, the release valve 51 opens for a brief discharge of fluid intothe return line 48 and the resultant drop in pressure instantly closesthe release valve 52, thus allowing valve 44 delivers fluid into theconduit 35 and the conduit 34- is communicated with the return line 48through the connection 50. In such instance the release valve 54 createspulsating pressure in the conduits 35, 32 and in the ring section 29!:to actuate the latter, while the ring section 29a in inactive.

In another mode of operation the valve 44 is closed, the valve 45 isopened, and the valve 49 is turned through 45' from the illustratedposition so that all four ports of the valve 49 are closed. Fluid thenflows from the pump through the open valve 45 and through both checkvalves 56, 57 to both conduits 34, 35, and hence through the conduits31, 32 to both ring sections 29a, 2%, the release valves 52, 54 againserving to produce pulsating pressure in the conduits and ring sections,but this time in both ring sections in unison. Thus, all the collarsegments 20a are alternately contracted and expanded in unison aroundthe entire circumference of the pile, as distinguished from impactingfirst one side and than the other side of the pile, as in the mode ofoperation first described.

Obviously, the four-way valve 49 may be either a sliding valve or arotary valve. Also, the two valves 44, 45 may be substituted by a singletwo-way valve, capable of delivering the pumped fluid either to thevalve 49 or to the valves 56, 57.

While in the foregoing there has been described and shown the preferredembodiment of the invention, various modifications may be resorted to,falling within the spirit and scope of the claims.

What is claimed as new is:

l. A dynamic driving shoe for placement on the lower end portion of apile which is driven into the earth by impacts delivered to its upperend; said shoe comprising a pile-encircling annulus, a radiallycontractable and expansible collar mounted on the inside of said annulusfor engagement with a pile, and hydraulically actuated means foralternately contracting and expanding said collar whereby to impartvibrations to the pile.

2. The device as defined in claim 1 wherein said hydrauli cally actuatedmeans include an expansible and contractable hollow ring interposedbetween said annulus and said collar, and means for delivering hydraulicfluid under pulsating pressure into said ring.

3. The device as defined in claim 2 wherein said collar includes aplurality of individual collar segments engaged by said ring.

4. The device as defined in claim 2 wherein said collar includes aplurality of individual collar segments engaged by said ring, said ringconsisting of at least two segmental ring sections which are isolatedfrom each other and are connected independently to said fluid-deliveringmeans, each of said ring sections spanning only a portion of the totalnumber of collar segments.

5. The device as defined in claim 4 wherein said fluiddelivering meansinclude atleast two conduits connected to the respective ring sections,a hydraulic pump, and valve means operable to deliver hydraulic fluidfrom said pump under pulsating pressure to said conduits selectively inunison or in alternating succession.

6. The device as defined in claim 1 wherein sad collar comprises aplurality of individual collar segments movable radially inwardly fromsaid annulus when the collar is contracted, and stop means provided onthe inside of the annulus for engagement by said collar segments tolimit their inward movement.

7. The device as defined in claim 6 together with resilient bumper meansinterposed between said collar segments and said stop means, said bumpermeans being resiliently compressed when the collar segments are movedinwardly and serving to bias the segments in the outward direction.

8. The device as defined in claim 6 which is further characterized inthat said collar segments are pivotally mounted in said annulus.

1. A dynamic driving shoe for placement on the lower end portion of apile which is driven into the earth by impacts delivered to its upperend; said shoe comprising a pile-encircling annulus, a radiallycontractable and expansible collar mounted on the inside of said annulusfor engagement with a pile, and hydraulically actuated means foralternately contracting and expanding said collar whereby to impartvibrations to the pile.
 2. The device as defined in claim 1 wherein saidhydraulically actuated means include an expansible and contractablehollow ring interposed between said annulus and said collar, and meansfor delivering hydraulic fluid under pulsating pressure into said ring.3. The device as defined in claim 2 wherein said collar includes aplurality of individual collar segments engaged by said ring.
 4. Thedevice as defined in claim 2 wherein said collar includes a plurality ofindividual collar segments engaged by said ring, said ring consisting ofat least two segmental ring sections which are isolated from each otherand are connected independently to said fluid-delivering means, each ofsaid ring sections spanning only a portion of the total number of collarsegments.
 5. The device as defined in claim 4 wherein saidfluid-delivering means include at least two conduits connected to therespective ring sections, a hydraulic pump, and valve means operable todeliver hydraulic fluid from said pump under pulsating pressure to saidconduits selectively in unison or in alternating succession.
 6. Thedevice as defined in claim 1 wherein sad collar comprises a plurality ofindividual collar segments movable radially inwardly from said annuluswhen the collar is contracted, and stop means provided on the inside ofthe annulus for engagement by said collar segments to limit their inwardmovement.
 7. The device as defined in claim 6 together with resilientbumper means interposed between said collar segments and said stopmeans, said bumper means being resiliently compressed when the collarsegments are moved inwardly and serving to bias the segments in theoutward direction.
 8. The device as defined in claim 6 which is furthercharacterized in that said collar segments are pivotally mounted in saidannulus.